3D Plots: add new plot types and improve features

[swharden]

The idea of 3D plots was mentioned previously (#2358) and recently implemented (#3774) but a lot of work is needed before this plot type feels truly functional. This issue will track progress toward moving forward with new features and plot types.

There is a new Sandbox.WinForms3D project in the ScottPlot 5 solution 🚀

High priority next steps that come to mind include:

• non-orthographic projection perspective (this may be a 2-line modification)
• improved center of rotation
• ability to render flat surfaces in 3D space by creating a polygon from their vertices
• addition of more 3D volume primitives
• fix 3D rectangles so their panel render order occurs farthest-to-closest
• a more carefully thought out UI which allows rotation along specific axes